Several adjustments
This commit is contained in:
topjohnwu
parent
caa39474cb
commit
2c4001387e
37
su.c
37
su.c
@ -22,7 +22,6 @@
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#include <libgen.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/auxv.h>
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#include <selinux/selinux.h>
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#include "magisk.h"
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@ -160,42 +159,6 @@ __attribute__ ((noreturn)) void exit2(int status) {
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}
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int su_daemon_main(int argc, char **argv) {
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// Sanitize all secure environment variables (from linker_environ.c in AOSP linker).
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/* The same list than GLibc at this point */
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static const char* const unsec_vars[] = {
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"GCONV_PATH",
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"GETCONF_DIR",
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"HOSTALIASES",
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"LD_AUDIT",
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"LD_DEBUG",
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"LD_DEBUG_OUTPUT",
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"LD_DYNAMIC_WEAK",
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"LD_LIBRARY_PATH",
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"LD_ORIGIN_PATH",
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"LD_PRELOAD",
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"LD_PROFILE",
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"LD_SHOW_AUXV",
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"LD_USE_LOAD_BIAS",
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"LOCALDOMAIN",
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"LOCPATH",
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"MALLOC_TRACE",
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"MALLOC_CHECK_",
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"NIS_PATH",
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"NLSPATH",
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"RESOLV_HOST_CONF",
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"RES_OPTIONS",
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"TMPDIR",
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"TZDIR",
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"LD_AOUT_LIBRARY_PATH",
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"LD_AOUT_PRELOAD",
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// not listed in linker, used due to system() call
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"IFS",
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NULL
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};
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if (getauxval(AT_SECURE))
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for (int i = 0; unsec_vars[i]; ++i)
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unsetenv(unsec_vars[i]);
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int c, socket_serv_fd, fd;
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char result[64];
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struct option long_opts[] = {
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205
su_daemon.c
205
su_daemon.c
@ -197,6 +197,106 @@ static struct su_info *get_su_info(unsigned uid) {
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return info;
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}
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static void su_executor(int client) {
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LOGD("su: executor started\n");
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// ack
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write_int(client, 0);
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// Become session leader
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xsetsid();
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// Migrate environment from client
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char path[32], buf[4096];
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snprintf(path, sizeof(path), "/proc/%d/cwd", su_ctx->pid);
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xreadlink(path, su_ctx->cwd, sizeof(su_ctx->cwd));
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snprintf(path, sizeof(path), "/proc/%d/environ", su_ctx->pid);
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memset(buf, 0, sizeof(buf));
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int fd = open(path, O_RDONLY);
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read(fd, buf, sizeof(buf));
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clearenv();
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for (size_t pos = 0; buf[pos];) {
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putenv(buf + pos);
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pos += strlen(buf + pos) + 1;
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}
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// Let's read some info from the socket
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int argc = read_int(client);
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if (argc < 0 || argc > 512) {
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LOGE("unable to allocate args: %d", argc);
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exit2(1);
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}
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LOGD("su: argc=[%d]\n", argc);
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char **argv = (char**) xmalloc(sizeof(char*) * (argc + 1));
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argv[argc] = NULL;
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for (int i = 0; i < argc; i++) {
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argv[i] = read_string(client);
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LOGD("su: argv[%d]=[%s]\n", i, argv[i]);
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// Replace -cn with -z, -mm with -M for supporting getopt_long
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if (strcmp(argv[i], "-cn") == 0)
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strcpy(argv[i], "-z");
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else if (strcmp(argv[i], "-mm") == 0)
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strcpy(argv[i], "-M");
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}
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// Get pts_slave
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char *pts_slave = read_string(client);
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// The FDs for each of the streams
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int infd = recv_fd(client);
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int outfd = recv_fd(client);
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int errfd = recv_fd(client);
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int ptsfd = -1;
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// We no longer need the access to socket in the child, close it
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close(client);
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if (pts_slave[0]) {
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LOGD("su: pts_slave=[%s]\n", pts_slave);
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// Check pts_slave file is owned by daemon_from_uid
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struct stat st;
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xstat(pts_slave, &st);
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// If caller is not root, ensure the owner of pts_slave is the caller
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if(st.st_uid != su_ctx->info->uid && su_ctx->info->uid != 0) {
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LOGE("su: Wrong permission of pts_slave");
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su_ctx->info->access.policy = DENY;
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exit2(1);
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}
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// Opening the TTY has to occur after the
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// fork() and setsid() so that it becomes
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// our controlling TTY and not the daemon's
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ptsfd = xopen(pts_slave, O_RDWR);
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if (infd < 0) {
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LOGD("su: stdin using PTY");
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infd = ptsfd;
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}
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if (outfd < 0) {
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LOGD("su: stdout using PTY");
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outfd = ptsfd;
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}
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if (errfd < 0) {
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LOGD("su: stderr using PTY");
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errfd = ptsfd;
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}
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}
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free(pts_slave);
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// Swap out stdin, stdout, stderr
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xdup2(infd, STDIN_FILENO);
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xdup2(outfd, STDOUT_FILENO);
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xdup2(errfd, STDERR_FILENO);
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close(ptsfd);
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// Run the actual main
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su_daemon_main(argc, argv);
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}
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void su_daemon_receiver(int client, struct ucred *credential) {
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LOGD("su: request from client: %d\n", client);
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@ -231,7 +331,11 @@ void su_daemon_receiver(int client, struct ucred *credential) {
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* send the return code back to our client
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*/
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int child = xfork();
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if (child) {
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if (child == 0) {
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su_ctx = &ctx;
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su_executor(client);
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}
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// Wait for results
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if (ctx.pipefd[0] >= 0) {
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xxread(ctx.pipefd[0], &ctx.info->access.policy, sizeof(policy_t));
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@ -273,105 +377,6 @@ void su_daemon_receiver(int client, struct ucred *credential) {
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sigaction(SIGPIPE, &act, NULL);
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return;
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}
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LOGD("su: child process started\n");
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// ack
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write_int(client, 0);
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// Become session leader
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xsetsid();
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// Migrate environment from client
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char path[32], buf[4096];
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snprintf(path, sizeof(path), "/proc/%d/cwd", ctx.pid);
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xreadlink(path, ctx.cwd, sizeof(ctx.cwd));
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snprintf(path, sizeof(path), "/proc/%d/environ", ctx.pid);
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memset(buf, 0, sizeof(buf));
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int fd = open(path, O_RDONLY);
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read(fd, buf, sizeof(buf));
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clearenv();
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for (size_t pos = 0; buf[pos];) {
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putenv(buf + pos);
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pos += strlen(buf + pos) + 1;
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}
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// Let's read some info from the socket
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int argc = read_int(client);
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if (argc < 0 || argc > 512) {
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LOGE("unable to allocate args: %d", argc);
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exit2(1);
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}
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LOGD("su: argc=[%d]\n", argc);
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char **argv = (char**) xmalloc(sizeof(char*) * (argc + 1));
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argv[argc] = NULL;
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for (int i = 0; i < argc; i++) {
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argv[i] = read_string(client);
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LOGD("su: argv[%d]=[%s]\n", i, argv[i]);
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// Replace -cn with -z, -mm with -M for supporting getopt_long
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if (strcmp(argv[i], "-cn") == 0)
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strcpy(argv[i], "-z");
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else if (strcmp(argv[i], "-mm") == 0)
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strcpy(argv[i], "-M");
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}
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// Get pts_slave
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char *pts_slave = read_string(client);
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LOGD("su: pts_slave=[%s]\n", pts_slave);
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// The FDs for each of the streams
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int infd = recv_fd(client);
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int outfd = recv_fd(client);
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int errfd = recv_fd(client);
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int ptsfd = -1;
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// We no longer need the access to socket in the child, close it
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close(client);
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if (pts_slave[0]) {
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// Check pts_slave file is owned by daemon_from_uid
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struct stat st;
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xstat(pts_slave, &st);
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// If caller is not root, ensure the owner of pts_slave is the caller
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if(st.st_uid != credential->uid && credential->uid != 0) {
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LOGE("su: Wrong permission of pts_slave");
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exit2(1);
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}
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// Opening the TTY has to occur after the
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// fork() and setsid() so that it becomes
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// our controlling TTY and not the daemon's
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ptsfd = xopen(pts_slave, O_RDWR);
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if (infd < 0) {
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LOGD("su: stdin using PTY");
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infd = ptsfd;
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}
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if (outfd < 0) {
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LOGD("su: stdout using PTY");
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outfd = ptsfd;
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}
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if (errfd < 0) {
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LOGD("su: stderr using PTY");
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errfd = ptsfd;
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}
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}
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free(pts_slave);
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// Swap out stdin, stdout, stderr
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xdup2(infd, STDIN_FILENO);
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xdup2(outfd, STDOUT_FILENO);
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xdup2(errfd, STDERR_FILENO);
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close(ptsfd);
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// Give main the reference
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su_ctx = &ctx;
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su_daemon_main(argc, argv);
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}
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/*
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